An Emergency Alert System (EAS) communicates emergency alert information to a population of people. One example of such a system is the United States EAS, which is designed to allow the President of the United States to speak directly to the general population of the United States within 10 minutes. Historically, communication channels utilized in connection with the United States EAS have been radio and television.
The prospect of including additional communication channels, especially communication to mobile devices, in an EAS is appealing because a great many people today carry mobile devices such as cellular telephones. Sending emergency alerts to mobile devices allows a great many more people to promptly receive alerts than would otherwise. For this reason, college campuses and other communities have introduced simplistic, opt-in EAS that send Short Message Service (SMS), or so-called text messages to mobile devices of those who subscribe to receive such messages, and may also send emergency alert emails to the relevant population.
In order for an EAS to function on a broader scale, however, it is desirable to broadcast emergency alerts to all mobile devices in a geographical area affected by an emergency condition, rather than simply send emergency alerts to a list of opt-in subscribers as in the example above. Broadcasting emergency alerts potentially eliminates the need to “opt-in” to receive emergency alerts, and also effectively communicates with all mobile devices in the affected area, regardless of whether such devices are in their “home” region or region for which they have opted to receive emergency alert information.
While broadcasting has clear advantages for sophisticated and large-scale EAS, so-called Third Generation (3G) and subsequent generation type mobile devices pose a problem in receiving broadcasted emergency alerts. Most 3G mobile devices can switch between radio communications with a cellular network, and wireless Internet Protocol (IP) or “Wi-Fi” type communications. When such a device enters a Wi-Fi hotspot, it will temporarily disable its cellular communications, and switch to Wi-Fi communications, because the Wi-Fi communications require less power and therefore present less drain on battery life. However, as a result of the switch, the device would no longer receive emergency alerts broadcasted from a cellular communications tower. Therefore, systems and methods are needed to communicate emergency alerts to mobile devices that have a first communications channel disabled while a second communications channel is active.